five
-1
Section::::History.:First systemization attempts.

Periodic table
23053
five
-1
Section::::Description.:Isotopic mass and atomic mass.

Chemical element
5659
five
-1
Section::::Abstract.
Halogen
13258
5
-1
Section::::Abstract.
Periodic table
23053
5
-1
Section::::Abstract.
Chemical element
5659
5
-1
Section::::History.

Halogen
13258